Lubricating oil composition



Patented July 25, 1944 UNITED STATES; P T N QQ 2.354.547. wamcarmc on. c'omosrrron Roger W. Richardson, Baton Rouge, La., and w Floyd L. Miller and Carl Winning, Westfleld, N. J., assignors to Standard Oil, Development 1 Company/3a corporation of Delaware 7 V No Drawing. Application August so,- 1941, a

Serial No. 409,034

i 9 Claims. ((1252-48) The present invention relates to improvements in lubricants and especially to the improvement of lubricating oils principally useful for internal combustion engines operating under severe conditions. The invention will 'befully understood from the following description.

Lubricating: oils which exhibit mproved performanc under all types of operating conditions when used for the lubrcation of heavy duty gasoline engines and for Diesel engines are coming into greater and greater demand. It has been proposed to add various ingredients to these oils to improve their behavior in such service, and the addition: of certain metal-containing organic compounds, such as metallic soaps, metallic phenolates and the like, to mineral lubricating oils results in bringing about greater engine-cleanli ness and avoidance of ring sticking, varnish formation and carbon deposition. One drawback to the use of such metallic compounds has been that by their use the deterioration of the oilis accelerated somewhat and corrosion of metal parts is promoted. This corrosive action of metallic soaps and the like is inhibited to som extent by, the-addition of certain'oth'er agents; At the same time, a considerable improvementin the condition of engines has resulted'inthe use of the addition agents described in combination with agents which inhibit their normalcorrosive action.

a It has been found that some addition agents .3

are not satisfactory when added to high viscosity index oils. Moreover, such metallic detergent agents have often not heretofore been found to be particularly satisfactory when'used with oils refined by the use of selective solvents. It has long been the belief that the best results from the use of the metallic detergent agents are obtained when they are used with nonextracted the unblended oil stock for two hours while the oil temperature is maintained at425 F. Such an oil is obtainable, for example, from parafllnic crudes produced in the Panhandle field; It isnot known just what component of the oil causes the production'of. the stain except thatsulfur is involved, since the stain contains sulfur. It is not caused by particularly large quantities of sulfur,

since many high sulfur oils do not have this property. ,It mayg'therefore, be due to sulfur present in some particular form, or the sulfur may play only a secondary role in causing the staining;

Tests of a variety of samples have shown that the stain producing property is associated with unusual cleanliness of the-engine in whichithey are/used. It seems probable that the stain paci-- fies the metallic surfaces, which normally .tend.

to hasten the deterioration of the metallic compounds added. By the use of an oil base having the characteristics described, the action of any deterioration preventing agent also present is aided and the normal corrosive action of the metallic additive is thereby further pacified. Furthermore, While the use of extracted oils has heretofore resulted in a low degree of engine cleanliness,'the results obtained on the use of stain producing base stocks, while slightly poorer in V the case of extracted oilsthan-inthe case of'acid treated oils, are. generallystill so .satisfactory that the extracted oils may advantageously be used in conjunction with the metallic additives.

The 'use of the stain producing base stock is particularly valuable in the production of oil's having. high viscosity indices, 1. e., over 70, in'

connection with which the metallic detergent agents may be used without the disadvantages formerly encountered when certain metallic additives were used with such oils.

The metallic. addition agents which maybe advantageously added to the stain producing lubri- I eating 011 base stocks of the present invention comprise particularly the metal salts of hydroxy organic compounds, for example, metallic phenolates, metal alcoholates, metallic aroxy sulfides and metallic enolates, and the metal salts of organic acids,for example, metallic soaps, metalthe metallic detergent agents hereinbefore de-'- 7 scribed. e g

It has been'found, in accordance with the-present invention, that outstanding performanceof these additives can be obtained if they are com pounded with base stocks characterized by hav-. ing, the property of imparting a dark blue to black stain to a steel surface when the steel, in the form of a bright steel strip, is immersed in lic salts of organo substituted phosphoric and salicyclic-acids, metallic xanthates, metallic sulfonates, and the like. These compounds may be added alone or preferably in conjunction with certain cooperating compounds, such as the high-;

er alcohols, amines, esters, ketones, ethers, 'etc. The metallic compounds are preferably added in quantities ranging from 0.05to 1.5%,; the particularly preferred limits being 0.2 to; 1.0%. 1

The lubricating oil base stock for the compositions' of the present invention may be any mineral oil base stock having the characteristic of staining-a steel surface'under the conditions described above and may be-"a ii'ractionr resulting from various physical and. chemical refining ore shown in Table n, wherein the letter designations for the base oils refer to the oils having treatments, such as solvent extraction; acid treatthe corresponding designation in Table 1. ing. selective precipitation; etc.. For the beat 7 results; however, the base stock chosen should I Table 11 be one which produce's substantially no stain on 3 I a copper strip inthe "conventional'A. S. T. M.

corrosion test, known as Standard TestDl30-30, Additives 5$, when conducted for one-half hour at a temperam tureor 212 F. For the lubrication of medium V and high speed'Diesel engines'it is general. prac- %.2??? t ary l fi i phenoxy M7 ticeto use a'lubricating oil base stock having a 4 252i; f gggg Saybolt viscosity at210 F. of 45 to so seconds. 7 iz 'g h l iliislooggt '1 phsnoxy sulfide 1.0a

whereas for aviation and similar services th s vis- 0 cosity may extend unto-150 seconds. :The viscos 23.2? Z'fsfirfi2fo2fi? phenow 'ityindex may vary over a :wide range; but, as 1%? ggeg g ggggg fgi zgi gfm gg stated above, theinvention isparticularly suited +0.25%stearylalcohoi to the use oi hlgh viscosity index oils, i. -e.-, those -'{,7;.,g; ggg, yg ggg 'aggf g; v having a viscosity index of '70. or above. 'Oils te ry alco having a viscosity index as high as 105 or higher 20 5"" %,,2? ,;.,,;LJ5f, Imam? are within the scope "of -he present nventionz B----- 3 gflg g ggg v v fi e 0. The oilsmay be free iro'm'other additionagents I 1%'-bo?rmm diisobutyl phenoxy sulfide -iass or. they may contain materials for particular 025% purposes, for example, thickeners, sludge dis persing. agents, dyes, pou'r depressants, viscosity index improvers, solvents, oiliness agents, and antioxidants. 7 g

V In the following examples oil blends made from various types oi. base stocks have beencompared in engine performance, tests. These examples are intended as illustrations only and-do not limit the scope of theinvention in any way.

2 1 Condition oi ring slits, grooves, lands and ring sides.

It is obvious that the performance or the vari ous oils varied widely but that the blend in oil 0 B provided definitely the cleanest engine conditions. Oil G, which causes slight staining in the steel strip test, showed up somewhat superior to the remaining oils. It should be noted that in V the demerit system the lower the rating the lights 7 Exaxrn lv or are the engine deposits. 1

Several types or lubricating oil base stocks, obtained-from various types of crudes and reflnedby diil'erent methods, were tested for their actionon cold rolledsteei strips (2" 'x 1" x 1%"),

at a temperature of 425 'Fnover a periodoi two hours. .The steel strips .were immersed in -the all contained in separate glass vessels andin the eating oils; also having base stocks selected from Y absence oi addition agents. The results of these those'tested for staining properties as described tests are shown in Table I. .in.Examp1e l, andncontaining various addition Exams: 3

Several normaltempera'ture tests were made on 40 a-single cylinder CaterpillarDiesel'engine I". atmospheric temperature, 140 F. oil temperature, 8503.. P.,M. engine speed) using various lubri- Table I I j Oil Method oi B. A. E. Appearance oi steel sample refining grade strip smitest Coastal naphthenic-..-.*. Acid treated" 42 30 No stain.

Panhan e parafflnio t E fed 98 20 Black stain. Mid-Continent parafllnic- .-...d 103 20 No stain.

do 20 Do. do 95 20 Do.

' Colombian naphthenic" 76 20 Do.

Smsckover high natural suliur-nsphthenic. 48 30 Very slight'stain. Pennsylvania c 99 20 No stain.

. o Extracted".-. 107 20 Do.

Panhandle parafllnic. Acid treated" 90 30 Black stain.

Midecontinent w do 88 20 No stain.

Coastalnsphthenic Extracted..." 68 30 Do.

EXAMPLE 2 agents. The duration of the tests and the engine 1 demr' b A number oi sixty hour tests in.a single cyline its 0 sewed are indicated in Table der Caterpillar Dieselengine were made under 7 Table In high temperature conditions F. atmospheric 65 V 7 temperature, F. oilrtemperature, 850 R. P. M. Base on Additives Hours 2:232 engine speed) using various lubricating-oils havdemerits ing base stocks selected from those described in V a 0.5"bait 4 1' Example l and having in addition small amounts z q g gg p n xv 113 1.30 of metalecontaining addition agentsof the type 7 M 0.57ifldcoE8i2t7gi-ts-1anliylt phenoxy 104 1.35

hereinbefore described. andsmall amounts of B lu ieiitw phenoxy 2G3 1.2a cooperating agents. At the completion of each s-0. m keloieate.

test the engine was dismantled. and the piston rated on a demerit system according to thede- 7 Again the superiority of the oil B blend is maniposits found onthe various parts. The'results 75 test, this product maintaining the engine in as EXAMPLE 4 Another series of sixty hour tests in a single cylinder Caterpillar Diesel engine were made under severe conditions, using lubricating oils containing additional oil base stocks selected from those described in Example 1. The oils were rated on a demerit system, accordin to which oil A, previously considered one of the best for Diesel engine service, was taken as the reference oil and given a demerit rating of 100. The other oils were rated in comparison with oil A on a percentage basis, the rating being adjusted to allow for some difierences in engine conditions in the various tests. The overall engine demerit ratings thus determined are shown in Table IV. All of the oils tested contained as additives 1% of barium diisobutyl phenoxy sulfide and 0.25% of stearyl alcohol.

Table IV Overall engine demerits (percent of reference) Bose oil Here, the blends oi the staining oils, L and l3,v

give outstandingly the best performance.

ExAuPLn 5 Table V Sludge Piston skirt blend demerit demerit on A plus additives 1.83 o. 75 Oil B plus additives 1.67 0. 58

In this engine also, the blend of the staining oil B performs the better.

The present invention is not to be considered as limited in any way by the various examples described herein, which are given by way of illustration only, but is to be limited in scope solely bythe terms of the appended claims.

We claim: 1. A lubricating oil for internal combustion engines comprising a minor proportion of a metal salt of a hydroxy organic compound and a major proportion of a refined mineral lubricating oil base stock capable of imparting a blue to black stain on a bright steel strip which has been immersed in said oil base stock in the absence of addition agents for two hours while the oil temperature is maintained at 425 F. v 2. A lubricating oil for internal combustion en- I gines comprising a minor proportion of a metal salt of a hydroxy organic compound and a major proportion of a refined mineral lubricating oil base stock capable of imparting a blue to black stain on a bright steel strip which has been immersed in said oil base stock in the absence of addition agents for two hours while the oil temperature was maintained at 425 F., said oil base stock producing substantially no stain on a copfor one-halt hour at a temperature Of 212 F.

3. A lubricating oil according to claim 2 in which the metal salt is a metallic aroxy sulfide. I 4. A lubricating oil according to claim 2 in which the metal salt is a metallic phenolate.

5. A lubricating oil according to claim 2 in which the metal salt is barium diisobutyl phenoxy sulfide.

6. A lubricating oil according to claim 2 in which the metal salt is a metallic aroxy sulfide and which contains in addition a small quantity of stearvl alcohol.

7. A lubricating oil according to claim-2 in which the base oil has been refined by solvent extraction.

8. An internal combustion engine lubricating.

oil composition having as a base oil a refined mineral lubricating oil which imparts substantially no stain to a copper strip in the standard A.-S. T. M. copper strip corrosion test when conducted ior one-half hour at 212 F. and which imparts a. blue to black stain to a bright steel strip which has been immersed in said oil base stock in the absence of addition agents for two hours while the oil temperature is maintained at 425 F., and. containing in addition to said oil base stock about 1% of barium diisobutyl phenoxy sulfide and about 0.25% of'stearyl alcohol.

9. A lubricating oil according to claim 2 in which the base oil has a viscosity index above 70.

ROGER W. RICHARDSON. FLOYD L. IVHLLER. CARL WINNING. 

